Variable-length guide apparatus for delivery of a flexible instrument and methods of use

ABSTRACT

An apparatus for guiding an elongated flexible instrument, includes a first plurality of linkages forming a first side of a channel of a variable-length support assembly, a second plurality of linkages forming a second side of the channel, opposite the first side, a third plurality of linkages disposed between the first and second plurality of linkages and forming a third side of the channel, and a fourth plurality of linkages disposed between the first and second plurality of linkages and forming a fourth side of the channel, opposite the third side. Each of the first, second, third, and fourth pluralities of linkages are separable from each other to transition the variable-length support assembly from an elongated configuration to a compact configuration.

RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 15/717,089 filed Sep. 27, 2017, which claims priority to andthe benefit of the filing date of U.S. Provisional Patent Application62/402,654, entitled “Variable-Length Guide Apparatus For Delivery Of AFlexible Instrument and Methods of Use,” filed Sep. 30, 2016, both ofwhich are incorporated by reference herein in their entirety.

FIELD

The present disclosure is directed to systems and methods for navigatinga patient anatomy to conduct a minimally invasive procedure, and moreparticularly to apparatus and methods for guiding and supportingdelivery of a flexible interventional instrument into a patient anatomy.

BACKGROUND

Minimally invasive medical techniques are intended to reduce the amountof tissue that is damaged during interventional procedures, therebyreducing patient recovery time, discomfort, and harmful side effects.Such minimally invasive techniques may be performed through naturalorifices in a patient anatomy or through one or more surgical incisions.Physicians may insert minimally invasive medical instruments (includingsurgical, diagnostic, therapeutic, or biopsy instruments) through thesenatural orifices or incisions to reach a target tissue location. Onesuch minimally invasive technique is to use a flexible and/or steerableelongate device, such as a flexible catheter, that can be inserted intoanatomic passageways and navigated toward a region of interest withinthe patient anatomy. To reach the target tissue location, a minimallyinvasive interventional instrument may navigate natural or surgicallycreated passageways in anatomical systems such as the lungs, the colon,the intestines, the kidneys, the heart, the circulatory system, or thelike. Control of such an elongate device by medical personnel involvesthe management of several degrees of freedom including at least themanagement of insertion and retraction of the elongate device as well assteering of the device. In addition, different modes of operation mayalso be supported.

Teleoperational interventional systems may be used to insert theinterventional instruments into the patient anatomy. Severalinterventional instruments are made of flexible material that allows formaneuverability through a patient's body. In existing systems, at leasta portion of the interventional instrument extending between the patientand a teleoperational manipulator is unsupported which may cause theinstrument to bend and buckle as it is inserted into the patientanatomy. Deformation of the instrument may damage internal componentssuch as optical fiber shape sensors or endoscopic equipment.

Improved systems and methods are needed for guiding and supportinginterventional instruments as they are inserted into a patient anatomyto prevent instrument deformation.

SUMMARY

The embodiments of the invention are summarized by the claims thatfollow the description.

In one embodiment, the present disclosure describes an apparatus forguiding an elongated flexible instrument, the apparatus comprising avariable-length support assembly. The variable-length support assemblyincludes a plurality of linkages connected in series along alongitudinal axis, and has a compact configuration and an expandedconfiguration. In one aspect, the variable-length support assembly isadapted to maintain a length of the elongated flexible instrument in afixed configuration relative to the variable-length support assembly asthe variable-length support assembly is moved along the longitudinalaxis.

In one aspect, the variable-length support assembly includes a centrallumen formed by the plurality of linkages, wherein the central channelis configured to receive the elongated flexible instrument.

In one aspect, at least two linkages of the plurality of linkages areconnected in series by a hinge component. In one aspect, each linkage ofthe plurality of linkages is movable relative to an adjacent linkageabout the hinge component.

In one aspect, each linkage of the plurality of linkages is configuredfor rotational movement about the hinge component relative to anadjacent linkage. In another aspect, each of the linkages is configuredfor linear translation about the hinge component relative to an adjacentlinkage.

In one aspect, the apparatus further comprises a return assemblyconfigured to receive at least one of the plurality of linkages toshorten the variable-length support assembly as the elongated flexibleinstrument is moved along the longitudinal axis.

In one aspect, the variable-length support assembly includes multiplestrips of linkages connected in series that are interlocked along thelongitudinal axis.

In another embodiment, the present disclosure describes a guidingapparatus comprising a variable-length support assembly that includes aplurality of linkages and a return assembly having a first centrallumen. The variable-length support assembly extends along a longitudinalaxis and has a second central lumen, a proximal end, and a distal end,in addition to an expanded configuration and a compact configuration.The return assembly is adjacent the proximal end of the variable-lengthsupport assembly. In one aspect, each linkage includes an inner surface,and each linkage is coupled to at least one adjacent linkage along thelongitudinal axis with the inner surfaces of the adjacent linkagesjoined to form a continuous second central lumen through thevariable-length support assembly. Advancement of the return assemblyalong the longitudinal axis separates the proximal end of the supportassembly, directing individual linkages into the return assembly andcausing the variable-length support assembly to assume the compactconfiguration.

In one aspect, the variable-length support assembly is adapted tomaintain a length of the elongated flexible instrument in a fixedconfiguration relative to the variable-length support assembly as thereturn assembly is moved along the longitudinal axis.

In one aspect, directing individual linkages into the return assemblycomprises rotating individual linkages away from away from the secondcentral lumen and the longitudinal axis.

In another aspect, directing individual linkages into the returnassembly comprises sliding individual linkages along the longitudinalaxis.

In one aspect, each linkage includes a projection and a recess, whereinthe projection of a first linkage of the plurality of linkagesinterlocks with the recess of a second linkage of the plurality oflinkages when the variable-length support assembly assumes an expandedconfiguration.

In one aspect, the return assembly comprises a hollow spiral configuredto receive a plurality of linkages.

In another embodiment, the present disclosure is directed to a method ofguiding an interventional instrument, the method comprising providing avariable-length support assembly extending along a longitudinal axis andhaving a proximal end, a distal end and a first length, the supportassembly including a plurality of linkages, with each linkage of theplurality of linkages interlocked with an adjacent linkage along thelongitudinal axis to form a continuous central lumen through thevariable-length support assembly. The method further comprises receivinga portion of the interventional instrument into the central lumen,moving the interventional instrument in a first direction along thelongitudinal axis, unlocking a linkage from an adjacent linkage, anddirecting the unlocked linkage in a second direction opposite the firstdirection into a return assembly.

In one aspect, unlocking a linkage from an adjacent linkage comprisesapplying force to the linkage to displace a projection of the linkagefrom a recess of the adjacent linkage.

In one aspect, unlocking a linkage from an adjacent linkage comprisesapplying force to the linkage to pivot the linkage at a hinge mechanismcoupling the linkage to an adjacent linkage.

In one aspect, directing the unlocked linkage in a second directionopposite the first direction into a return assembly comprises rotatingthe unlocked linkage away from the central lumen.

In one aspect, directing the unlocked linkage in a second directionopposite the first direction into a return assembly comprises slidingthe unlocked linkage in the first direction toward an adjacent linkage.

In one aspect, directing the unlocked linkage in a second directionopposite the first direction into a return assembly comprises shorteningthe first length of the variable-length support assembly to a secondlength of the variable-length support assembly.

In another embodiment, the present disclosure is directed to anapparatus for guiding an elongated flexible instrument, the apparatuscomprising a first plurality of linkages forming a first side of achannel of a support assembly, a second plurality of linkages forming asecond side of the channel, opposite the first side, a third pluralityof linkages interlocked between the first and second plurality oflinkages and forming a third side of the channel, and a fourth pluralityof linkages interlocked between the first and second plurality oflinkages and forming a fourth side of the channel, opposite the thirdside. Advancement of the support assembly along a longitudinal axisdefined through the channel causes an asynchronous unlocking of thefirst, second, third, and fourth plurality of linkages from each other.

In another embodiment, the present disclosure is directed to anapparatus for guiding an elongated flexible instrument, the apparatuscomprising a plurality of linkages, each coupled by a hinge to anadjacent linkage of the plurality of linkages. The plurality of linkageshave an elongated configuration in which the plurality of linkages arehelically wound with each linkage of the plurality of linkagesinterlocked with a non-adjacent linkage to form a channel of avariable-length support assembly. In one aspect, the plurality oflinkages have a splayed configuration in which each linkage of theplurality of linkages is unlocked from the non-adjacent linkage and isrotated about and translated along an axis of the hinge relative to theadjacent linkage of the plurality of linkages.

In another embodiment, the present disclosure is directed to anapparatus for guiding an elongated flexible instrument, the apparatuscomprising a first plurality of linkages forming a first side of achannel of a support assembly and a second plurality of linkages forminga second side of the channel, opposite the first side. In one aspect, inan elongated configuration of the support assembly, each linkage of thefirst plurality of linkages is interlocked between two linkages of thesecond plurality of linkages, and each linkage of the first plurality oflinkages is hingedly coupled to an adjacent linkage of the firstplurality of linkages by a bridging element that maintains a spacingbetween the linkage and the adjacent linkage. The support assemblytransitions from the elongated configuration to a separatedconfiguration as the support assembly is advanced along a longitudinalaxis defined by the channel, and, in the separated configuration, eachlinkage of the plurality of linkages is unlocked from between the twolinkages of the second plurality of linkages.

Additional aspects, features, and advantages of the present disclosurewill become apparent from the following detailed description.

BRIEF DESCRIPTIONS OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isemphasized that, in accordance with the standard practice in theindustry, various features are not drawn to scale. In fact, thedimensions of the various features may be arbitrarily increased orreduced for clarity of discussion. In addition, the present disclosuremay repeat reference numerals and/or letters in the various examples.This repetition is for the purpose of simplicity and clarity and doesnot in itself dictate a relationship between the various embodimentsand/or configurations discussed.

FIG. 1 is a simplified diagram of a teleoperated medical system, inaccordance with embodiments of the present disclosure.

FIG. 2A is a simplified diagram of a medical instrument system accordingto some embodiments of the present disclosure.

FIG. 2B is a simplified diagram of a medical instrument with an extendedmedical tool according to some embodiments of the present disclosure.

FIG. 3 is a simplified diagram of a side view of a teleoperationalmanipulator assembly, an elongate instrument, and an instrument guidingapparatus according to some embodiments of the present invention.

FIG. 4 illustrates a schematic side view of the distal end of theinstrument guiding apparatus of FIG. 3 in an initial configuration.

FIGS. 5A and 5B illustrate perspective views of an exemplary linkagesubset according to one embodiment of the present disclosure. FIG. 5Aillustrates a perspective view of the linkage subset in a partially“unzipped” or inactive configuration. FIG. 5B illustrates a moredetailed perspective view of particular linkages of the exemplarylinkage subset shown in FIG. 5A.

FIGS. 6A-6H illustrate various views of the linkage subset illustratedin FIG. 5A. In particular. FIG. 6A illustrates a front view of thelinkage subset illustrated in FIG. 5A. FIG. 6B illustrates a back viewof the linkage subset illustrated in FIG. 5A. FIG. 6C illustrates aright side view of the linkage subset illustrated in FIG. 5A. FIG. 6Dillustrates a left side view of the linkage subset illustrated in FIG.5A. FIG. 6E illustrates a top view of the linkage subset illustrated inFIG. 5A. FIG. 6F illustrates a bottom view of the linkage subsetillustrated in FIG. 5A. FIGS. 6G and 6H illustrate front, partiallytransparent views of the linkage subset 320.

FIGS. 7A-7F illustrate various views of an exemplary linkage of thelinkage subset illustrated in FIG. 5A. FIG. 7A illustrates a front viewof the linkage. FIG. 7B illustrates a back view of the linkage. FIG. 7Cillustrates a right side view of the linkage. FIG. 7D illustrates a leftside view of the linkage. FIG. 7E illustrates a top view of the linkage.FIG. 7F illustrates a bottom view of the linkage.

FIGS. 8A and 8B illustrate an exemplary linkage subset of an instrumentguiding apparatus according to an embodiment of the present disclosure.FIG. 8A illustrates the exemplary linkage subset in a compactconfiguration. FIG. 8B illustrates the exemplary linkage subset in anexpanded configuration.

FIGS. 9A and 9B illustrate the linkage subset shown in FIG. 5A in a“zipped” or active configuration. FIG. 9A illustrates a partiallytransparent perspective view of the linkage subset, and FIG. 9Billustrates a top view of the linkage subset.

FIG. 10 illustrates a perspective view of an exemplary linkage subset ofan instrument guiding apparatus according to an embodiment of thepresent disclosure.

FIG. 11 illustrates a schematic side view of the distal end of theinstrument guiding apparatus of FIG. 4 in a partially “unzipped” orinactive configuration according to an embodiment of the presentinvention.

FIG. 12 illustrates the interventional instrument and instrument guidingapparatus of FIGS. 3 and 4 coupled to a teleoperational manipulatorassembly in a patient environment according to an embodiment of thepresent invention.

FIGS. 13A-13C illustrate side views of an exemplary instrument guidingapparatus including the linkage subset shown in FIG. 5A according to oneembodiment of the present disclosure.

FIG. 14 illustrates an exemplary return assembly according to oneembodiment of the present disclosure.

FIG. 15 is a flowchart describing a method of guiding an interventionalinstrument according to an embodiment of the present disclosure.

FIGS. 16A-16G illustrate various views of an exemplary linkage subset.In particular, FIG. 16A illustrates a front view of the linkage subset.FIG. 6B illustrates a back view of the linkage subset. FIG. 16Cillustrates a right side view of the linkage subset. FIG. 16Dillustrates a left side view of the linkage subset. FIG. 16E illustratesa top view of the linkage subset. FIG. 16F illustrates a bottom view ofthe linkage subset.

FIG. 17 illustrates a schematic diagram of the unfolding and foldingmechanism of the linkage subset illustrated in FIGS. 16A-16G as ittransitions from an active to an inactive configuration.

FIG. 18 illustrates a perspective view of an exemplary linkage subsetaccording to another embodiment of the present disclosure.

FIGS. 19A-19E illustrate various views of the exemplary linkage subsetshown in FIG. 18 coupled to an exemplary return assembly. In particular.FIG. 19A illustrates a front view of the linkage subset and returnassembly. FIG. 19B illustrates a back view of the linkage subset andreturn assembly. FIG. 19C illustrates a right side view of the linkagesubset and return assembly. FIG. 19D illustrates a top view of thelinkage subset and return assembly. FIG. 19E illustrates a bottom viewof the linkage subset and return assembly.

FIG. 20 illustrates a perspective view of an exemplary linkage subsetcoupled to an exemplary return assembly.

FIGS. 21A-21G illustrate various views of the exemplary linkage subsetand the exemplary return assembly shown in FIG. 20 . In particular, FIG.21A illustrates another perspective view of the linkage subset and thereturn assembly. FIG. 21B illustrates the same perspective view as FIG.21A of the linkage subset with a transparent view of the returnassembly. FIG. 21C illustrates a front view of the linkage subset and atransparent view of the return assembly. FIG. 21D illustrates a rightside view of the linkage subset and the return assembly. FIG. 21Eillustrates a left side view of the linkage subset and the returnassembly.

FIG. 21F illustrates a top view of the linkage subset and the returnassembly. FIG. 21G illustrates a bottom view of the linkage subset andthe return assembly.

DETAILED DESCRIPTION

In the following description, specific details are set forth describingsome embodiments consistent with the present disclosure. Numerousspecific details are set forth in order to provide a thoroughunderstanding of the embodiments. It will be apparent, however, to oneskilled in the art that some embodiments may be practiced without someor all of these specific details. The specific embodiments disclosedherein are meant to be illustrative but not limiting. One skilled in theart may realize other elements that, although not specifically describedhere, are within the scope and the spirit of this disclosure. Inaddition, to avoid unnecessary repetition, one or more features shownand described in association with one embodiment may be incorporatedinto other embodiments unless specifically described otherwise or if theone or more features would make an embodiment non-functional.

In some instances well known methods, procedures, components, andcircuits have not been described in detail so as not to unnecessarilyobscure aspects of the embodiments.

This disclosure describes various instruments and portions ofinstruments in terms of their state in three-dimensional space. As usedherein, the term “position” refers to the location of an object or aportion of an object in a three-dimensional space (e.g., three degreesof translational freedom along Cartesian x-, y-, and z-coordinates). Asused herein, the term “orientation” refers to the rotational placementof an object or a portion of an object (three degrees of rotationalfreedom—e.g., roll, pitch, and yaw). As used herein, the term “pose”refers to the position of an object or a portion of an object in atleast one degree of translational freedom and to the orientation of thatobject or portion of the object in at least one degree of rotationalfreedom (up to six total degrees of freedom). As used herein, the term“shape” refers to a set of poses, positions, or orientations measuredalong an object.

FIG. 1 is a simplified diagram of a teleoperated medical system 100according to some embodiments. In some embodiments, teleoperated medicalsystem 100 may be suitable for use in, for example, surgical,diagnostic, therapeutic, or biopsy procedures. As shown in FIG. 1 ,medical system 100 generally includes a teleoperational manipulatorassembly 102 for operating a medical instrument 104 in performingvarious procedures on a patient P. Teleoperational manipulator assembly102 is mounted to or near an operating table T. A master assembly 106allows an operator O (e.g., a surgeon, a clinician, or a physician asillustrated in FIG. 1 ) to view the interventional site and to controlteleoperational manipulator assembly 102.

Master assembly 106 may be located at a user's console which is usuallylocated in the same room as operating table T, such as at the side of asurgical table on which patient P is located. However, it should beunderstood that operator O can be located in a different room or acompletely different building from patient P. Master assembly 106generally includes one or more control devices for controllingteleoperational manipulator assembly 102. The control devices mayinclude any number of a variety of input devices, such as joysticks,trackballs, data gloves, trigger-guns, hand-operated controllers, voicerecognition devices, body motion or presence sensors, and/or the like.To provide operator O a strong sense of directly controlling instruments104 the control devices may be provided with the same degrees of freedomas the associated medical instrument 104. In this manner, the controldevices provide operator O with telepresence or the perception that thecontrol devices are integral with medical instruments 104.

In some embodiments, the control devices may have more or fewer degreesof freedom than the associated medical instrument 104 and still provideoperator O with telepresence. In some embodiments, the control devicesmay optionally be manual input devices which move with six degrees offreedom, and which may also include an actuatable handle for actuatinginstruments (for example, for closing grasping jaws, applying anelectrical potential to an electrode, delivering a medicinal treatment,and/or the like).

The teleoperational assembly 102 supports the medical instrument system104 and may include a kinematic structure of one or more non-servocontrolled links (e.g., one or more links that may be manuallypositioned and locked in place, generally referred to as a set-upstructure) and a teleoperational manipulator. The teleoperationalassembly 102 includes plurality of actuators or motors that drive inputson the medical instrument system 104 in response to commands from thecontrol system (e.g., a control system 112). The motors include drivesystems that when coupled to the medical instrument system 104 mayadvance the medical instrument into a naturally or surgically createdanatomic orifice. Other motorized drive systems may move the distal endof the medical instrument in multiple degrees of freedom, which mayinclude three degrees of linear motion (e.g., linear motion along the X,Y, Z Cartesian axes) and in three degrees of rotational motion (e.g.,rotation about the X, Y, Z Cartesian axes). Additionally, the motors canbe used to actuate an articulable end effector of the instrument forgrasping tissue in the jaws of a biopsy device or the like. Motorposition sensors such as resolvers, encoders, potentiometers, and othermechanisms may provide sensor data to the teleoperational assemblydescribing the rotation and orientation of the motor shafts. Thisposition sensor data may be used to determine motion of the objectsmanipulated by the motors.

The teleoperational medical system 100 also includes a sensor system 108with one or more sub-systems for receiving information about theinstruments of the teleoperational assembly. Such sub-systems mayinclude a position/location sensor system (e.g., an electromagnetic (EM)sensor system); a shape sensor system for determining the position,orientation, speed, velocity, pose, and/or shape of the catheter tipand/or of one or more segments along a flexible body of instrumentsystem 104; and/or a visualization system for capturing images from thedistal end of the catheter system.

The visualization system (e.g., visualization system 231 of FIG. 2A) mayinclude a viewing scope assembly that records a concurrent or real-timeimage of the surgical site and provides the image to the operator O,clinician, or surgeon. The concurrent image may be, for example, a twoor three dimensional image captured by an endoscope positioned withinthe surgical site. In this embodiment, the visualization system includesendoscopic components that may be integrally or removably coupled to themedical instrument 104. However in alternative embodiments, a separateendoscope, attached to a separate manipulator assembly may be used withthe medical instrument to image the surgical site. The visualizationsystem may be implemented as hardware, firmware, software or acombination thereof which interact with or are otherwise executed by oneor more computer processors, which may include the processors of acontrol system 112 (described below). The processors of the controlsystem 112 may execute instructions comprising instruction correspondingto processes disclosed herein.

The teleoperational medical system 100 also includes a display system110 for displaying an image or representation of the surgical site andmedical instrument system(s) 104 generated by sub-systems of the sensorsystem 108. The display system 110 and the operator O input system 106may be oriented so the operator O can control the medical instrumentsystem 104 and the operator O input system 106 with the perception oftelepresence.

The display system 110 may also display an image of the surgical siteand medical instruments captured by the visualization system. Thedisplay system 110 and the control devices may be oriented such that therelative positions of the imaging device in the scope assembly and themedical instruments are similar to the relative positions of theoperator's eyes and hands so the operator O can manipulate the medicalinstrument 104 and the hand control as if viewing the workspace insubstantially true presence. By true presence, it is meant that thepresentation of an image is a true perspective image simulating theviewpoint of an operator O that is physically manipulating theinstrument 104.

Alternatively or additionally, the display system 110 may present imagesof the surgical site recorded pre-operatively or intra-operatively usingimage data from imaging technology such as, computed tomography (CT),magnetic resonance imaging (MRI), fluoroscopy, thermography, ultrasound,optical coherence tomography (OCT), thermal imaging, impedance imaging,laser imaging, or nanotube X-ray imaging. The pre-operative orintra-operative image data may be presented as two-dimensional,three-dimensional, or four-dimensional (including e.g., time based orvelocity based information) images or as images from models created fromthe pre-operative or intra-operative image data sets.

In some embodiments often for purposes of imaged guided surgicalprocedures, the display system 110 may display a virtual navigationalimage in which the actual location of the medical instrument 104 isregistered (i.e., dynamically referenced) with the preoperative orconcurrent images/model to present the clinician or operator O with avirtual image of the internal surgical site from the viewpoint of thelocation of the tip of the instrument 104. In some examples, theviewpoint may be from a tip of medical instrument 104. An image of thetip of the instrument 104 or other graphical or alphanumeric indicatorsmay be superimposed on the virtual image to assist theoperatorcontrolling the medical instrument. Alternatively, theinstrument 104 may not be visible in the virtual image.

In other embodiments, the display system 110 may display a virtualnavigational image in which the actual location of the medicalinstrument is registered with preoperative or concurrent images topresent the clinician or operator O with a virtual image of medicalinstrument within the surgical site from an external viewpoint. An imageof a portion of the medical instrument or other graphical oralphanumeric indicators may be superimposed on the virtual image toassist the operatorcontrolling the instrument 104. As described herein,visual representations of data points may be rendered to the displaysystem 110. For example, measured data points, moved data points,registered data points, and other data points described herein may bedisplayed on the display system 110 in a visual representation. The datapoints may be visually represented in a user interface by a plurality ofpoints or dots on the display or as a rendered model, such as a mesh orwire model created based on the set of data points. In some embodiments,a visual representation may be refreshed in the display system 110 aftereach processing operations has been implemented to alter the datapoints.

The teleoperational medical system 100 also includes a control system112. The control system 112 includes at least one memory and at leastone computer processor (not shown), and typically a plurality ofprocessors, for effecting control between the medical instrument system104, the operator input system 106, the sensor system 108, and thedisplay system 110. The control system 112 also includes programmedinstructions (e.g., a non-transitory machine-readable medium storing theinstructions) to implement some or all of the methods described inaccordance with aspects disclosed herein, including instructions forproviding pathological information to the display system 110. Whilecontrol system 112 is shown as a single block in the simplifiedschematic of FIG. 1 , the system may include two or more data processingcircuits with one portion of the processing optionally being performedon or adjacent the teleoperational assembly 102, another portion of theprocessing being performed at the operator input system 106, anotherportion of the processing being performed at master assembly 106, andthe like. The processors of control system 112 may execute instructionscomprising instruction corresponding to processes disclosed herein anddescribed in more detail below. Any of a wide variety of centralized ordistributed data processing architectures may be employed. Similarly,the programmed instructions may be implemented as a number of separateprograms or subroutines, or they may be integrated into a number ofother aspects of the teleoperational systems described herein. In oneembodiment, control system 112 supports wireless communication protocolssuch as Bluetooth, IrDA, HomeRF, IEEE 802.11, DECT, and WirelessTelemetry.

In some embodiments, control system 112 may receive force and/or torquefeedback from medical instrument 104. Responsive to the feedback,control system 112 may transmit signals to master assembly 106. In someexamples, control system 112 may transmit signals instructing one ormore actuators of teleoperational manipulator assembly 102 to movemedical instrument 104. Medical instrument 104 may extend into aninternal surgical site within the body of patient P via openings in thebody of patient P. Any suitable conventional and/or specializedactuators may be used. In some examples, the one or more actuators maybe separate from, or integrated with, teleoperational manipulatorassembly 102. In some embodiments, the one or more actuators andteleoperational manipulator assembly 102 are provided as part of ateleoperational cart positioned adjacent to patient P and operatingtable T.

The control system 112 may further include a virtual visualizationsystem to provide navigation assistance to operator O when controllingthe medical instrument system(s) 104 during an image-guided surgicalprocedure. Virtual navigation using the virtual visualization system isbased upon reference to the acquired preoperative or intraoperativedataset of the anatomic passageways. The virtual visualization systemprocesses images of the surgical site imaged using imaging technologysuch as computerized tomography (CT), magnetic resonance imaging (MRI),fluoroscopy, thermography, ultrasound, optical coherence tomography(OCT), thermal imaging, impedance imaging, laser imaging, nanotube X-rayimaging, or the like. Software, which may be used in combination withmanual inputs is used to convert the recorded images into segmented twodimensional or three dimensional composite representation of a partialor an entire anatomic organ or anatomic region. An image data set isassociated with the composite representation. The compositerepresentation and the image data set describe the various locations andshapes of the passageways and their connectivity. The images used togenerate the composite representation may be recorded preoperatively orintra-operatively during a clinical procedure. In some embodiments, avirtual visualization system may use standard representations (i.e., notpatient specific) or hybrids of a standard representation and patientspecific data. The composite representation and any virtual imagesgenerated by the composite representation may represent the staticposture of a deformable anatomic region during one or more phases ofmotion (e.g., during an inspiration/expiration cycle of a lung).

During a virtual navigation procedure, the sensor system 108 may be usedto compute an approximate location of the instrument with respect to theanatomy of patient P. The location can be used to produce bothmacro-level (external) tracking images of the anatomy of patient P andvirtual internal images of the anatomy of patient P. For example U.S.patent application Ser. No. 13/107,562 (filed May 13, 2011) (disclosing“Medical System Providing Dynamic Registration of a Model of an AnatomicStructure for Image-Guided Surgery”) which is incorporated by referenceherein in its entirety, discloses one such system.

The teleoperational medical system 100 may further include optionaloperation and support systems (not shown) such as illumination systems,steering control systems, irrigation systems, and/or suction systems. Insome embodiments, the teleoperational system may include more than oneteleoperational assembly and/or more than one master assembly. The exactnumber of manipulator assemblies will depend on the surgical procedureand the space constraints within the operating room, among otherfactors. Master assembly 106 may be collocated or they may be positionedin separate locations. Multiple master assemblies allow more than oneoperator to control one or more teleoperational manipulator assembliesin various combinations.

FIG. 2A is a simplified diagram of a medical instrument system 200according to some embodiments. In some embodiments, medical instrumentsystem 200 may be used as medical instrument 104 in an image-guidedmedical procedure performed with teleoperated medical system 100. Insome examples, medical instrument system 200 may be used fornon-teleoperational exploratory procedures or in procedures involvingtraditional manually operated medical instruments, such as endoscopy.Optionally medical instrument system 200 may be used to gather (i.e.,measure) a set of data points corresponding to locations within anatomicpassageways of a patient, such as patient P.

The instrument system 200 includes an elongate device 202 (e.g., acatheter system) coupled to a drive unit 204. The elongate device 202includes an elongated flexible body 216 having a proximal end 217 and adistal end or tip portion 218. In one embodiment, the flexible body 216has an approximately 3 mm outer diameter. Other flexible body outerdiameters may be larger or smaller. The catheter system 202 mayoptionally include a shape sensor 222 for determining the position,orientation, speed, velocity, pose, and/or shape of the catheter tip atdistal end 218 and/or of one or more segments 224 along the body 216.The entire length of the body 216, between the distal end 218 and theproximal end 217, may be effectively divided into the segments 224. Ifthe instrument system 200 is a medical instrument system 104 of ateleoperational medical system 100, the shape sensor 222 may be acomponent of the sensor system 108. If the instrument system 200 ismanually operated or otherwise used for non-teleoperational procedures,the shape sensor 222 may be coupled to a tracking system 230 thatinterrogates the shape sensor and processes the received shape data.

Medical instrument system 200 further includes a tracking system 230 fordetermining the position, orientation, speed, velocity, pose, and/orshape of distal end 218 and/or of one or more segments 224 alongflexible body 216 using one or more sensors and/or imaging devices asdescribed in further detail below. The entire length of flexible body216, between distal end 218 and proximal end 217, may be effectivelydivided into segments 224. If medical instrument system 200 isconsistent with medical instrument 104 of a teleoperated medical system100, tracking system 230. Tracking system 230 may optionally beimplemented as hardware, firmware, software or a combination thereofwhich interact with or are otherwise executed by one or more computerprocessors, which may include the processors of control system 112 inFIG. 1 .

Tracking system 230 may optionally track distal end 218 and/or one ormore of the segments 224 using a shape sensor 222. Shape sensor 222 mayoptionally include an optical fiber aligned with flexible body 216(e.g., provided within an interior channel (not shown) or mountedexternally). In one embodiment, the optical fiber has a diameter ofapproximately 200 μm. In other embodiments, the dimensions may be largeror smaller. The optical fiber of shape sensor 222 forms a fiber opticbend sensor for determining the shape of flexible body 216. In onealternative, optical fibers including Fiber Bragg Gratings (FBGs) areused to provide strain measurements in structures in one or moredimensions. Various systems and methods for monitoring the shape andrelative position of an optical fiber in three dimensions are describedin U.S. patent application Ser. No. 11/180,389 (filed Jul. 13, 2005)(disclosing “Fiber optic position and shape sensing device and methodrelating thereto”); U.S. patent application Ser. No. 12/047,056 (filedon Jul. 16, 2004) (disclosing “Fiber-optic shape and relative positionsensing”); and U.S. Pat. No. 6,389,187 (filed on Jun. 17, 1998)(disclosing “Optical Fibre Bend Sensor”), which are all incorporated byreference herein in their entireties. Sensors in some embodiments mayemploy other suitable strain sensing techniques, such as Rayleighscattering, Raman scattering. Brillouin scattering, and Fluorescencescattering. In some embodiments, the shape of the elongate device may bedetermined using other techniques. For example, a history of the distalend pose of flexible body 216 can be used to reconstruct the shape offlexible body 216 over the interval of time. In some embodiments,tracking system 230 may optionally and/or additionally track distal end218 using a position sensor system 220. Position sensor system 220 maybe a component of an EM sensor system with positional sensor system 220including one or more conductive coils that may be subjected to anexternally generated electromagnetic field. Each coil of EM sensorsystem 220 then produces an induced electrical signal havingcharacteristics that depend on the position and orientation of the coilrelative to the externally generated electromagnetic field. In someembodiments, position sensor system 220 may be configured and positionedto measure six degrees of freedom, e.g., three position coordinates X.Y. Z and three orientation angles indicating pitch, yaw, and roll of abase point or five degrees of freedom, e.g., three position coordinatesX, Y, Z and two orientation angles indicating pitch and yaw of a basepoint. Further description of a position sensor system is provided inU.S. Pat. No. 6,380,732 (filed Aug. 11, 1999) (disclosing “Six-Degree ofFreedom Tracking System Having a Passive Transponder on the Object BeingTracked”), which is incorporated by reference herein in its entirety.

In some embodiments, tracking system 230 may alternately and/oradditionally rely on historical pose, position, or orientation datastored for a known point of an instrument system along a cycle ofalternating motion, such as breathing. This stored data may be used todevelop shape information about flexible body 216. In some examples, aseries of positional sensors (not shown), such as electromagnetic (EM)sensors similar to the sensors in position sensor 220 may be positionedalong flexible body 216 and then used for shape sensing. In someexamples, a history of data from one or more of these sensors takenduring a procedure may be used to represent the shape of elongate device202, particularly if an anatomic passageway is generally static.

Flexible body 216 includes a channel 221 sized and shaped to receive amedical instrument 226. FIG. 2B is a simplified diagram of flexible body216 with medical instrument 226 extended according to some embodiments.In some embodiments, medical instrument 226 may be used for proceduressuch as surgery, biopsy, ablation, illumination, irrigation, or suction.Medical instrument 226 can be deployed through channel 221 of flexiblebody 216 and used at a target location within the anatomy. Medicalinstrument 226 may include, for example, image capture probes, biopsyinstruments, laser ablation fibers, and/or other surgical, diagnostic,or therapeutic tools. Medical tools may include end effectors having asingle working member such as a scalpel, a blunt blade, an opticalfiber, an electrode, and/or the like. Other end effectors may include,for example, forceps, graspers, scissors, clip appliers, and/or thelike. Other end effectors may further include electrically activated endeffectors such as electrosurgical electrodes, transducers, sensors,and/or the like. In various embodiments, medical instrument 226 is abiopsy instrument, which may be used to remove sample tissue or asampling of cells from a target anatomic location. Medical instrument226 may be used with an image capture probe also within flexible body216. In various embodiments, medical instrument 226 may be an imagecapture probe that includes a distal portion with a stereoscopic ormonoscopic camera at or near distal end 218 of flexible body 216 forcapturing images (including video images) that are processed by avisualization system 231 for display and/or provided to tracking system230 to support tracking of distal end 218 and/or one or more of thesegments 224. The image capture probe may include a cable coupled to thecamera for transmitting the captured image data. In some examples, theimage capture instrument may be a fiber-optic bundle, such as afiberscope, that couples to visualization system 231. The image captureinstrument may be single or multi-spectral, for example capturing imagedata in one or more of the visible, infrared, and/or ultravioletspectrums. Alternatively, medical instrument 226 may itself be the imagecapture probe. Medical instrument 226 may be advanced from the openingof channel 221 to perform the procedure and then retracted back into thechannel when the procedure is complete. Medical instrument 226 may beremoved from proximal end 217 of flexible body 216 or from anotheroptional instrument port (not shown) along flexible body 216.

Medical instrument 226 may additionally house cables, linkages, or otheractuation controls (not shown) that extend between its proximal anddistal ends to controllably the bend distal end of medical instrument226. Steerable instruments are described in detail in U.S. Pat. No.7,316,681 (filed on Oct. 4, 2005) (disclosing “Articulated SurgicalInstrument for Performing Minimally Invasive Surgery with EnhancedDexterity and Sensitivity”) and U.S. patent application Ser. No.12/286,644 (filed Sep. 30, 2008) (disclosing “Passive Preload andCapstan Drive for Surgical Instruments”), which are incorporated byreference herein in their entireties.

Flexible body 216 may also house cables, linkages, or other steeringcontrols (not shown) that extend between drive unit 204 and distal end218 to controllably bend distal end 218 as shown, for example, by brokendashed line depictions 219 of distal end 218. In some examples, at leastfour cables are used to provide independent “up-down” steering tocontrol a pitch of distal end 218 and “left-right” steering to control ayaw of distal end 281. Steerable elongate devices are described indetail in U.S. patent application Ser. No. 13/274,208 (filed Oct. 14,2011) (disclosing “Catheter with Removable Vision Probe”), which isincorporated by reference herein in its entirety. In embodiments inwhich medical instrument system 200 is actuated by a teleoperationalassembly, drive unit 204 may include drive inputs that removably coupleto and receive power from drive elements, such as actuators, of theteleoperational assembly. In some embodiments, medical instrument system200 may include gripping features, manual actuators, or other componentsfor manually controlling the motion of medical instrument system 200.Elongate device 202 may be steerable or, alternatively, the system maybe non-steerable with no integrated mechanism for operator control ofthe bending of distal end 218. In some examples, one or more lumens,through which medical instruments can be deployed and used at a targetsurgical location, are defined in the walls of flexible body 216.

In some embodiments, medical instrument system 200 may include aflexible bronchial instrument, such as a bronchoscope or bronchialcatheter, for use in examination, diagnosis, biopsy, or treatment of alung. Medical instrument system 200 is also suited for navigation andtreatment of other tissues, via natural or surgically created connectedpassageways, in any of a variety of anatomic systems, including thecolon, the intestines, the kidneys and kidney calices, the brain, theheart, the circulatory system including vasculature, and/or the like.

The information from tracking system 230 may be sent to a navigationsystem 232 where it is combined with information from visualizationsystem 231 and/or the preoperatively obtained models to provide theoperator or other user with real-time position information. In someexamples, the real-time position information may be displayed on displaysystem 110 of FIG. 1 for use in the control of medical instrument system200. In some examples, control system 116 of FIG. 1 may utilize theposition information as feedback for positioning medical instrumentsystem 200. Various systems for using fiber optic sensors to registerand display a surgical instrument with surgical images are provided inU.S. patent application Ser. No. 13/107,562, filed May 13, 2011,disclosing. “Medical System Providing Dynamic Registration of a Model ofan Anatomic Structure for Image-Guided Surgery,” which is incorporatedby reference herein in its entirety.

In some examples, medical instrument system 200 may be teleoperatedwithin medical system 100 of FIG. 1 . In some embodiments,teleoperational manipulator assembly 102 of FIG. 1 may be replaced bydirect operator control. In some examples, the direct operator controlmay include various handles and operator interfaces for hand-heldoperation of the instrument.

When using a teleoperational assembly to insert an instrument catheterinto a patient anatomy, the outstretched catheter should be supported asthe catheter is advanced into the patient. Otherwise, as the catheter ispushed from a proximal end and encounters friction in the patientanatomy at the distal end, the catheter may buckle or bend. To preventthis deformation of the catheter, an instrument guiding apparatus, asdescribed herein, may be used to provide relatively rigid support to thecatheter until it enters the patient anatomy. As the catheter enters thepatient anatomy, the effective length of guiding apparatus decreases asportions of the apparatus fold away from or “unzip” along the catheterand move to an unobtrusive location. In some embodiments, the guidingapparatus feeds into a storage device as it “unzips” or disengages fromthe catheter. Thus, because the effective length of the guidingapparatus varies with the position of the catheter relative to thepatient, the maximum length of the catheter may be used for patienttreatment.

FIG. 3 illustrates an instrument interface portion 300 of ateleoperational manipulator assembly (e.g. teleoperational manipulatorassembly 102) and an instrument guiding apparatus 302 according to anembodiment of the present invention. The instrument interface portion300 includes drive inputs 304 to provide mechanical coupling of theinstrument end effector and flexible body steering mechanism to thedrive motors mounted to the teleoperational manipulator. For example, apair of drive inputs may control the pitch motion of the distal end ofthe instrument flexible body, with one adaptor of the pair controllingmotion in the upward direction and the other of the pair controllingmotion in the opposite downward direction. Other pairs of drive inputsmay provide opposing motion in other degrees of freedom for the flexiblebody and/or the end effector. Instrument interfacing withteleoperational or robotic manipulators is described, for example inU.S. Pat. No. 6,331,181, filed Oct. 15, 1999, disclosing “SurgicalRobotic Tools, Data Architecture, And Use” and U.S. Pat. No. 6,491,701,filed Jan. 12, 2001 disclosing “Mechanical Actuator Interface System ForRobotic Surgical Tools” which are both incorporated by reference hereinin their entirety. The instrument interface portion 300 may also controlinstrument insertion by moving linearly along an insertion axis A.

The instrument guiding apparatus 302 has a distal end 301 and a proximalend 303. The instrument guiding apparatus 302 includes a variable-lengthsupport assembly 306 and a mounting strut 307 for coupling theinstrument interface portion 300 to the assembly 306. In the picturedembodiment, the instrument guiding apparatus 302 includes a returnassembly 308. In some embodiments, the variable-length support assembly306 collapses or folds into the return assembly 308 as the instrumentinterface portion 300 advances toward the patient, thereby applying alinear force to the variable-length support assembly 306 in thedirection of arrow A1 along the axis A.

The distal end 301 of the instrument guiding apparatus 302 is shown indetail in FIG. 4 in an initial configuration. The variable-lengthsupport assembly 306 includes a plurality of linkages 310 connected inseries by hinge components 312. In some embodiments, the linkages 310may be arranged in subsets of linkages that form a repeating pattern oflinkages throughout the length of the variable-length support assembly306. For example, in this embodiment, the linkages 310 are arranged inlinkage subsets 314 that form a repeating pattern of linkages 310 a, 310b, 310 c, 310 d, 310 e. Individual linkages 310 and/or individuallinkage subsets 314 may be substantially identical to one other, or maydiffer in size, shape, and/or material composition. In some embodiments,the hinge components 312 connect the adjacent linkages 310 in a spiralfashion, as described in further detail below with reference to FIGS. 5and 6A-6D. In other embodiments, as described below with respect toFIGS. 16A-16E, 18, and 19A-19C, the hinge components 312 connect theadjacent linkages 310 in a more linear fashion. The hinge components 312allow for movement between the linkages 310 in one or more degrees offreedom. In some embodiments, for example, the hinge components mayallow for linear translation as well as rotational movement between thelinkages 310. In the pictured embodiment, the return assembly 308 iscoupled to the proximal-most linkages 310 of the variable-length supportassembly 306, and a coupling element 309 links the return assembly 308proximal-most linkages 310 of the variable-length support assembly 306to the mounting strut 307. In the pictured embodiment, the elongatedsupport assembly includes a stabilizing element 311, which may be usedto stabilize the elongated support assembly relative to the operatingfield. Other embodiments may lack the stabilizing element 311.

As shown in FIG. 4 , the variable-length support assembly 306 includes acentral channel or lumen 315. The linkages 310 are connected andconfigured to allow the passage of a medical instrument such as, by wayof non-limiting example, a catheter, through the central lumen 315. Inthe pictured embodiment, the central lumen 315 of the variable-lengthsupport assembly 306 is continuous with a central lumen 317 of thereturn assembly 308. Both central lumens 315 and 317 are sized andshaped to allow for the passage of a medical instrument such as, by wayof non-limiting example, a catheter, through both the variable-lengthsupport assembly 306 and the return assembly 308.

FIGS. 5A-5B and 6A-6H illustrate various views of a linkage subset 320,which is an exemplary linkage subset 314 of the variable-length supportassembly 306 described above with reference to FIG. 4 according to oneembodiment of the present disclosure. FIG. 5A illustrates a perspectiveview of the linkage subset 320, and FIG. 5B illustrates a more detailedperspective view of the linkages 310 c-310 e shown in FIG. 5A. FIG. 6Aillustrates a front view of the linkage subset 320. FIG. 6B illustratesa back view of the linkage subset 320. FIG. 6C illustrates a right sideview of the linkage subset 320. FIG. 6D illustrates a left side view ofthe linkage subset 320. FIG. 6E illustrates a top view of the linkagesubset 320. FIG. 6F illustrates a bottom view of the linkage subset 320.FIGS. 6G and 6H illustrate front, partially transparent views of thelinkage subset 320.

The linkage subset 320 comprises five individual linkages 310 a, 310 b.310 c, 310 d, and 310 e aligned around a central axis CA. Each linkage310 a-e is coupled to adjacent linkages in series. For example, thelinkage 310 a is coupled to the linkage 310 b, the linkage 310 b iscoupled to the linkages 310 c and 310 a, the linkage 310 c is coupled tothe linkages 310 d and 310 c, and the linkage 310 d is coupled to thelinkages 310 e and 310 c. In FIGS. 5 and 6A-6F, the linkage subset 320is shown in a partially “unzipped” or inactive configuration, with thelinkage 310 e outwardly rotated in the direction of arrow AA about avertical axis VA. In contrast, the linkage subset 320 is shown in a“zipped” or active configuration in FIGS. 9A. 9B, and 12A, with eachlinkage 310 a-e snugly coupled to the adjacent linkage and rotatedinward in the direction of arrow A2 toward the central axis CA.

As shown in FIGS. 5A, 5B, and 6A-6D, in the pictured embodiment, eachlinkage 310 a-e is shaped as an irregular hemi-cylinder with a convexouter surface 325 a-e and a concave inner surface 330 a-e, respectively.In other embodiments, each linkage may be shaped as any type of partialcylinder (i.e., any fraction of a cylinder cut along its axial length).The linkages 310 a-e each include a first recess 335 a-e and secondrecess 340 a-e on the inner surfaces 330 a-e, respectively. In FIGS. 5Aand 5B, the linkage 310 e is shown rotated outwardly from the centralaxis CA, revealing the first recess 335 e and the second recess 340 e ofthe linkage 310 e.

In the pictured embodiment, the linkages 310 a-e are identical to oneanother in shape and size. In other embodiments, the individual linkages310 a-e may differ in shape and/or size from one another. Before furtherdescribing how the linkages 310 a-e interact with one another to form aportion (i.e., the linkage subset 314) of the variable-length supportassembly 306 described above with reference to FIG. 4 , an individuallinkage will be described. In particular, the linkage 310 d isillustrated in detail in FIGS. 7A-7F. FIG. 7A illustrates a front viewof the linkage 310 d. FIG. 7B illustrates a back view of the linkage 310d. FIG. 7C illustrates a right side view of the linkage 310 d. FIG. 7Dillustrates a left side view of the linkage 310 d. FIG. 7E illustrates atop view of the linkage 310 d. FIG. 7F illustrates a bottom view of thelinkage 310 d.

The linkage 310 d includes a projection 345 d and a body portion 350 d.The body portion 350 d extends from an upper surface 352 d to a lowersurface 354 d. In the pictured embodiment, the upper surface 352 d andthe lower surface 354 d share matching angles of curvatures or slopeprofiles. Thus, the upper and lower surfaces 352, 354 of bothimmediately adjacent and non-adjacent linkages 310 can smoothly meet andrest against one another as the linkages 310 spiral into an active or“zipped up” configuration. For example, when the linkage 320 is in a“zipped” or active configuration, the upper surface 352 d of the linkage310 d contacts the lower surface 352 a of the linkage 310 a as well asthe lower surface 352 b of the linkage 310 b. The upper and lowersurfaces 352 d, 354 d may be generally planar abutment surfaces and/ormay include keyed features for interconnection with mating features ofan adjacent linkage 310.

As described above, FIGS. 6G and 6H illustrate front, partiallytransparent views of the linkage subset 320 that allows bettervisualization of how the linkages 310 interact with one another. Inparticular, FIG. 6G illustrates a front view of the linkage subset 320with a transparent view of the linkage 310 c. FIG. 6H illustrates afront view of the linkage subset 320 with a transparent view of thelinkage 310 d. The body portion 350 d of the linkage 310 d includes afirst recess 335 d upon the inner surface 330 d, which is sized andshaped to receive the projection 345 of a serially connected,nonadjacent linkage (i.e., the projection 345 a of the linkage 310 a, asshown in FIG. 6A and FIG. 6G). The body portion 350 d also includes asecond recess 340 d upon the inner surface 330 d, which is sized andshaped to receive the projection 345 of a serially connected, adjacentlinkage (i.e. the projection 345 b of the linkage 310 b, as shown inFIGS. 6B and 6H).

Referring back to FIG. 5B, the pictured embodiment illustrates theinteraction between the linkages 310 c. 310 d, and 310 e. In particular,the body portion 350 e includes a first recess 335 e, which is sized andshaped to receive a projection 345 b of the serially connected,nonadjacent linkage 310 b. The body portion 350 e also includes a secondrecess 340 e, which is sized and shaped to receive the projection 345 cof a serially connected, nonadjacent linkage 310 c. Thus, when thelinkage subset 320 is in a “zipped” or active configuration, theprojections 345 of the individual linkages 310 nest within the recesses335, 340 of neighboring linkages, thereby releasably “locking” thelinkages 310 together and enhancing the structural stability of thevariable-length support assembly 306. The projections 345 and recesses335, 340 allow the linkages 310 to function in a similar manner to theteeth of a zipper, with each linkage 310 locking another linkage 310into place in the variable-length support assembly 306 while preservinga channel within which the medical instrument may travel.

As indicated by FIGS. 6E and 6F, when the linkage subset 320 is in a“zipped” or active configuration, the inner surfaces 330 of the linkages310 form a generally continuous, cylindrical lumen 355. The lumens 355of several linkage subsets (e.g., the linkage subsets 314) combine toform the central lumen 315 of the variable-length support assembly 306shown in FIG. 4 .

Each linkage 310 in the linkage subset 320 is connected to the twoadjacent linkages via pivot pins 342, 344 (not shown) that extendthrough the body portion 350. In this embodiment, the pivot pins 410 actas the hinge components 312 shown in FIG. 4 . The pivot pins 342, 344allow for both translational movement between the linkages 310 along thecentral axis and rotational movement between the linkages 310 about thepivot pins 342 (for example, in the direction of arrow AA in FIG. 5 andarrow A2 in FIG. 9A). For example, a first pivot pin 342 (not shown)extends from within an upper channel 360 d in the body portion 350 dinto a lower channel 365 c (not shown in FIGS. 7A-7F) of the adjacentlinkage 310 c, thus hingedly coupling the adjacent linkages. Similarly,a second pivot pin 344 (not shown) extends from within a lower channel370 d into an upper channel 360 e (not shown in FIGS. 7A-7F) of theadjacent linkage 310 e, thus hingedly coupling the adjacent linkages.The pivot pins 342, 344 operate in a manner similar to the pivot pins410 described below with reference to FIGS. 8A and 8B.

In the embodiments pictured herein, the linkages 310 a-c and 310 e ofthe linkage subset 320 are identical in shape and size to the linkage310 d described above with reference to FIGS. 7A-7F. The linkages 310a-e may be formed of any of a variety of rigid or semi-rigid materialsincluding metals, polymers, or rubber. In various alternativeembodiments, the linkage subsets 314 may have fewer or more than fivelinkages. Within each linkage subset 320, each linkage 310 a-e hasindividual upper channels 360 a-e, lower channels 365 a-e, curved uppersurfaces 352 a-e, and lower surfaces 354 a-e.

FIGS. 8A and 8B illustrate exemplary linkage subsets 400 of aninstrument guiding apparatus according to an embodiment of the presentdisclosure. FIG. 8A illustrates the exemplary linkage subset 400 in asplayed and compact configuration. FIG. 8B illustrates exemplary linkagesubsets 400 in a splayed and expanded configuration. The linkage subset400 is substantially similar to the linkage subset 320 described aboveexcept as described below. In particular, the linkage subset 400includes at least nine linkages 405 coupled by pivot pins 410. Thelinkages 405 are substantially similar to the linkages 310 describedabove. FIGS. 8A and 8B illustrate the translational movement between thelinkages 405 enabled by the pivot pins 410.

In FIG. 8A, the linkages 405 are in a compact configuration, with anupper surface 412 of each linkage 405 positioned as far apart from theneighboring upper surface 412 as the pivot pins 410 would allow. Asshown in FIG. 8A, the pivot pins 410 are partially exposed, extendingfrom upper channels 415 and lower channels 420 within the linkages 405.If force is applied upon the linkages 405 in the direction of the uppersurfaces 412, as indicated by the arrow A3, the linkages 405 slide inthe same direction upon the pivot pins 410 to reveal the pivot pins 410and assume a compact, “unzipped,” and splayed or inactive configuration.

In FIG. 8B, the linkages 405 are shown in an expanded configuration,with the upper surface 412 of each linkage 405 positioned adjacent tothe neighboring upper surface 412 to create a generally continuous lineof upper surfaces 412 indicated by the dotted line. In FIG. 8B, thelinkages 405 are shown slid apart from one another along the pivot pins410 such that the pivot pins 410 are largely positioned with the upperchannels 415 and the lower channels 420. If force is applied on thelinkages 405 in the direction of projections 425, as indicated by thearrow A4 (e.g., in the opposite direction of the arrow A3 shown in FIG.8A), then the linkages 405 slide apart from one another along the pivotpins 410, sheathing the pivot pins 410 within the upper channels 415 andlower channels 420 of the linkages 405. Thus, as the linkages 310 of thevariable-length support assembly 306 “zip” or “unzip,” the linkages 310both pivot and slide along the pivot pins 410 to lock and unlock fromone another.

FIGS. 9A and 9B illustrate the linkage subset 320 in a “zipped” oractive configuration. In particular, FIG. 9A illustrates a partiallytransparent perspective view of the linkage subset 320 in a “zipped” oractive configuration, and FIG. 9B illustrates a top view of the linkagesubset 320 in an elongated “zipped” or active configuration. Thelinkages 310 a-e are shaped and sized such that when serially assembledin such a “zipped” or active configuration, the convex outer surfaces325 a-e form a generally continuous outer surface of the cylindricalvariable-length support assembly 306. When several linkage subsets 320are interlocked in such a “zipped” or active configuration, the innersurfaces 330 a-e of each of the linkages 310 are aligned such that thechannels 335 of each of the linkage subsets 320 are linearly alignedgenerally along the insertion axis A to form the continuous centrallumen 315 extending through the variable-length support assembly 306shown in FIG. 4 . In other alternative embodiments, the diameter of thechannels 335 of the linkage subsets 320 may be sized to accommodatedifferent diameter catheters. In still other alternative embodiments,the diameter of the channels 335 of different linkage subsets may varyalong the length of the variable-length support assembly 306 to matchthe diameter of a catheter with a diameter varying along its length.

FIG. 10 illustrates a detailed view of an exemplary linkage subset 320′according to one embodiment of the present disclosure. The linkagesubset 320′ includes at least the linkages 310 c′, 310 d′, and 310 e′.The linkages 310 c′, 310 d′, and 310 e′ are substantially identical tothe linkages 310 c, 310 d, and 310 e described above except for thedifferences described herein. Although the linkages 310 in theembodiments described above exhibit a right-handed helical pattern ofassembly into the “zipped” or active configuration, the linkages 310′ ofthe linkage subset 320′ exhibit a left-handed helical pattern ofassembly into the “zipped” or active configuration.

FIG. 11 illustrates a schematic side view of the distal end of theinstrument guiding apparatus 302 of FIG. 4 in a partially “unzipped” orinactive configuration according to an embodiment of the presentinvention. As the return assembly 308 is advanced distally toward thepatient along the insertion axis A in the direction of the arrow A1, thereturn assembly 308 acts as an effective “zipper pull” that operates to“unzip” the variable-length support assembly 306 by nudging theproximal-most linkages 310 apart and into the return assembly 308.

FIG. 12 illustrates an interventional instrument 500 and the instrumentguiding apparatus 302 of FIGS. 3 and 4 coupled to a teleoperationalmanipulator assembly 550 in a patient environment according to anembodiment of the present invention. The teleoperational manipulatorassembly 550 includes the instrument interface portion 300. Theinstrument 500 is positioned in a surgical environment with a patientanatomy P. As shown in FIG. 12 , the instrument system 500 includes anelongated flexible catheter 502 extending generally along the insertionaxis A when the instrument system is coupled to the teleoperationalinterface portion 300. In operation, as illustrated in FIG. 12 ,movement of the instrument interface portion 300 distally along the axisA advances the mounting strut 307 which moves the proximal end 303 ofthe variable-length support assembly 306 distally (i.e. toward thepatient anatomy P). As the proximal end 303 of the variable-lengthsupport assembly 306 is moved distally, the proximal-most linkages 310slide toward one another along the axis A and “unzip” or unwind, withthe individual linkages 310 nearest the return assembly 308 rotatingoutward from and sliding distally on the pivot pins 410 along the axis Abefore entering the return assembly 308. These outwardly rotatedlinkages 310 are directed to the return assembly 308, as illustrated inFIG. 11 .

An opeartor may insert the catheter 502 into the central lumen 317 ofthe return assembly 308 and the central lumen 315 of the elongatedsupport assembly (introduced in FIG. 4 ) to support the longitudinallength of the catheter 502 throughout the process of insertion into thepatient anatomy P. Regardless of the angle of insertion, the catheter502 is generally able to flex slightly to conform to the entry angleinto the central lumens 315, 317. Inside the variable-length supportassembly 306, the flexible catheter 502 returns to a generally straightconfiguration within the continuous central lumen 315 (which, asdescribed above, is formed by the inner surfaces 330 of the linkages310). As the instrument interface portion 300 is advanced, under theoperator's control, distally along the insertion axis A, it also movesthe catheter 502 and the proximal end 303 of the instrument guidingapparatus 302 distally. As the instrument interface portion 300 and thecatheter 502 are advanced distally along the axis A toward the patientanatomy P, the variable-length support assembly 306 shortens as theproximal-most linkages 310 are “unzipped” and fed into the returnassembly 308, as indicated by FIG. 11 . At the proximal end 303 of theinstrument guiding apparatus 302, the return assembly 308 incrementallyseparates the variable-length support assembly 306 into “unlocked”linkages 310 that routed into the return guide 308. As the proximal-mostlinkages 310 are directed into the return assembly 308, the catheter 502continues to advance distally past the distal end 301 of the instrumentguiding apparatus 302 for insertion into the patient anatomy P. As thevariable-length support assembly 306 shortens in accord with thediminishing external portion of the catheter 502, the central lumen 315remains continuous along the remaining “zipped-up” linkages. Thus, theflexible catheter 502 is continuously supported along its externallength (i.e. the portion of the catheter 502 that has not yet enteredthe patient anatomy P) within the variable-length support assembly 306as it enters the patient anatomy P. As the catheter 502 is removed fromthe patient anatomy P, the return assembly 308 moves in reverse,releasing the linkages 310 to support the withdrawn catheter 502. Thereleased linkages 310 are biased to reassemble (i.e., slide proximallydown the pivot pins 410 to allow the projections 345 to “lock” into thechannels 340, 355) into the gradually lengthening interlockedvariable-length support assembly 306.

As described above, the variable-length support assembly 306 can supportthe catheter 502 shown in FIG. 12 along its changing external (i.e.,positioned outside the patient anatomy P) length as it enters or exitsthe patient anatomy P. With the linkages 310 interlocked along theinsertion axis A, the support assembly 306 minimizes bending or bucklingof the catheter 502 as the distal end of the catheter 502 is advancedinto the patient anatomy P. Any significant bending or buckling of thecatheter 502 may damage optical fibers used for shape sensing orendoscopy. Also, bending or buckling may make advancing the catheternon-intuitive, since the user will observe no distal tip movement eventhough the user is advancing the proximal end of the catheter. In thedescribed embodiments, the linkages 310 form a self-supporting structurethat requires no support rails or other rigid, elongated supports alongthe axis A. Thus, the proximal-most linkages 310 are able to move out ofthe path of the advancing teleoperational interface portion 300 byreceding into the return assembly 308. As compared to a telescopingsupport assembly that includes linkages that circumferentially telescopeinto one another in a traditional manner, the variable-length supportassemblies described herein support the entire exposed length of thecatheter 502 as it advances proximally along the axis of insertion A.

FIGS. 13A-13C more clearly illustrate the mechanics of a variable-lengthsupport assembly as it “unzips” or assumes an inactive configuration toenter the return assembly 308. FIGS. 13A-13C illustrate side views of anexemplary variable-length support assembly 600 including the linkagesubset 320 shown in FIG. 5A according to one embodiment of the presentdisclosure. In the pictured embodiment, the variable-length supportassembly 600 includes at least two additional linkages 310′ and 310″. InFIGS. 13A and 13B, a catheter 605 extends through a central lumen 610 ofthe variable-length support assembly 600. In FIG. 13A, thevariable-length support assembly 600 is in a “zipped” or activeconfiguration, with each linkage 310 locked to an adjacent linkage 310to form the central lumen 610. The catheter 605 can slide within thecentral lumen 610, but it remains in a relatively straight configurationwithin the lumen 610. When the linkages 310 are in a “zipped” or activeconfiguration, the central lumen 610 has an initial length L1.

In FIG. 13B, the variable-length support assembly 600 is in a partially“unzipped” or inactive configuration, with the linkages 310 c-eunwinding or “unzipping” from each other by rotating outward in thedirection of arrow A4 and sliding upward in the direction of arrow A5along the pivot pins (not shown). As a force F is applied on thevariable-length support assembly 600 in the direction of the arrow A5,the linkages 310 are forced to slide in the direction of A5 and biased(e.g., by the curvature of the upper surfaces 352 and lower surfaces 354of the linkages 310) to rotate outward in the direction of arrow A4 whenthe extent of the sliding movement is reached. The central lumen 610 nowhas a smaller length L2. Consequently, a shorter length of the catheter605 is supported within the central lumen 610 because the length L2 ofthe central lumen is less than the original length L1 of the centrallumen.

In FIG. 13C, the variable-length support assembly 600 is in an entirely“unzipped” or inactive configuration, with the linkages 310 a-e, 310′,and 310″ unwound or “unzipped” from each other after rotating outward inthe direction of arrow A4 and sliding upward in the direction of arrowA5 along the pivot pins (not shown). As shown in FIG. 13C, as thevariable-length support assembly 600 unwinds or “unzips,” the linkages310 wind around one another to form a spiral shape resembling a nautilusshell.

FIG. 14 illustrates an exemplary return assembly 650 according to oneembodiment of the present disclosure. As mentioned above with referenceto FIG. 11 , as the instrument interface portion 300 and the catheter502 are advanced distally along the axis A toward the patient anatomy P,the variable-length support assembly 306 shortens as the proximal-mostlinkages 310 are “unzipped” and fed into the return assembly 308. In usewith any of the variable-length support assemblies described above, thereturn assembly 650 would serve as a “zipper pull” traveling in thedistal direction, nudging the proximal-most linkages to slide along thepivot pins 410 in the distal direction along the axis A before rotatingoutwards (i.e. “unzipping”) to enter the return assembly 650. Similarly,if the return assembly 650 is moved in the proximal direction along theaxis A, the linkages 310 would emerge from the return assembly 650,rotate inwards, and slide proximally along the pivot pins 410 until thelinkages “locked” together once again and the variable-length supportassembly 306 lengthened, regaining at least a partially “zipped” oractive configuration.

In the pictured embodiment, the return assembly 650 is shaped as ahollow spiral resembling a nautilus shell. The shape and dimensions ofthe return assembly 650 are designed to complement the shape anddimensions of any one of the variable-length support assembliesdescribed above. In particular, the return assembly 650 is sized andshaped to nudge the linkages 310 apart (e.g., to urge the proximal-mostlinkage 310 to slide distally and rotate outwardly on the pivot pin410), to guide these linkages 310 into the return assembly 650, and toaccommodate the linkages 310 in an “unzipped” configuration within apassageway 655. In the pictured embodiment, the passageway 655 is shapedas a spiral channel. In some embodiments, the return assembly includesan entrance and exit ramp 660 designed to facilitate and direct thesmooth entry and exit of the linkages 310 from the passageway 655. Theentrance and exit ramps 660 may be sized and shaped to direct thelinkages 310 at a constant speed into the passageway 655 of the returnassembly 650. In alternate embodiments, the steepness of the ramps 660may be different from that shown in the pictured embodiment. Inparticular, the ramp steepness or angle may be altered to enable ashorter or more compact storage configuration (which may, however, causehigher friction of the linkages sliding on the ramp).

FIG. 15 is a flowchart 700 describing a method of guiding aninterventional instrument (e.g., the instrument 500) using theinstrument guiding apparatus 302. At 705, the method 700 includesreceiving a catheter portion of an interventional instrument into aninstrument guiding apparatus, and, in particular, into a variable-lengthsupport assembly. As described above, the catheter may be inserted intoa continuous central lumen of the variable-length support assembly. Inmost instances, the variable-length support assembly is in a “zipped-up”or active configuration, with the adjacent linkages locked into oneanother along the length of the support assembly. At 710, the method 700includes receiving an indication at the teleoperational control systemthat the interventional instrument system is coupled to theteleoperational manipulator. At 715, the method 700 includes advancingthe interventional instrument system, including the return assembly,along the insertion axis A. At 720, the method 700 includesincrementally “unwinding” or “unzipping” the proximal end of thevariable-length support assembly into individual linkages by applyingforce to the proximal end of the support assembly, thereby sliding theproximal-most linkages outward and distally along their pivot pins. Asthe variable-length support assembly is incrementally unzipped, thedistal catheter portion of the interventional instrument is advanceddistally into the patient anatomy. The proximal portion of the catheterremains supported by the interlocked, “zipped-up” distal portion of thevariable-length support assembly. At 725, the method 700 includessheathing the proximal-most linkages within the return assembly, therebyshortening the length of the variable-length support assembly as thecatheter enters the patient anatomy.

FIGS. 16A-16G illustrate various views of an exemplary linkage subset800. In particular. FIG. 16A illustrates a front view of the linkagesubset 800. FIG. 6B illustrates a back view of the linkage subset 800.FIG. 16C illustrates a right side view of the linkage subset 800. FIG.16D illustrates a left side view of the linkage subset 800. FIG. 16Eillustrates a top view of the linkage subset 800. FIG. 16F illustrates abottom view of the linkage subset 800. The linkage subset 800 is anexample of the linkage subset 314 of the variable-length supportassembly 306 described above with reference to FIG. 4 according to oneembodiment of the present disclosure.

In the pictured embodiment, the linkage subset 800 comprises 11individual linkages 805 a-k serially coupled to one another. Asillustrated by the linkages 805 i-k in FIG. 16A, which are substantiallyidentical to the other linkages 810 a-h (except for alternating linkages805 including two slots 807, 808 and an aperture 809), each linkage 805is shaped as a relatively flat tab including two hinge tips 810 at oneend and two hinge pins 815 at the opposing end. The linkage 805 jincludes a body portion 820 j integrally and rigidly connected to aflange portion 825 j. The flat and generally rectangular shape of thebody portions 820 and the arcuate shape of the flange portions 825should not be considered a limiting feature, as other shapes andconfigurations of the linkages are contemplated for other embodiments ofthe present invention. These may include, for example, round,rectangular, oblong, elliptical, triangular, and square shapes. Thehinge tips 810 of each linkage 805 are shaped and sized to interact withthe hinge pins 815 of an adjacent linkage 805 to create a hingemechanism that pivotally connects adjacent linkages 805.

When assembled into an elongated support assembly 306, each alternatinglinkage 805 includes two slots 807, 808 and the aperture 809 within thebody portion 820. For example, in the illustrated embodiment of FIG.16A, the linkages 805 a, 805 b, 805 h, 805 f, and 805 k each include twoslots 807 and the aperture 809. The slots 807 are shaped and sized toreceive individual flange portions 825 of other linkages 805 when thelinkage subset 800 is in an active or “zipped-up” configuration. Theapertures 809 are shaped and sized to receive individual hingemechanisms of other linkages 805 when the linkage subset 800 is in anactive or “zipped-up” configuration. FIGS. 16A-16G show the linkages 805a-h assembled together in an active or “zipped up” configuration, withthe flange portions 825 a-h positioned within the appropriate slots 807and 808. For example, FIG. 16A illustrates the upper slot 807 breceiving the flange portion 825 a and the lower slot 808 b receivingthe flange portion 825 e.

As best shown by the top and bottom views of the linkage subset 800illustrated in FIGS. 16F and 16G, the linkage subset 800 is formed offour strips of linkages 805 that are connected at right angles to form acentral lumen 830. Each strip of linkages 805 forms a support member.The central lumen 830 corresponds to the central lumen 315 describedabove with reference to FIG. 4 .

As best illustrated by the linkages 805 i-k in FIGS. 16B and 16C,alternating linkages 805 are coupled to each other via the hingemechanisms, i.e., the hinge pins 815 connect to the hinge tips 810.Moreover, the adjacent linkages 805 are reversed or flipped such thatthe hinge tips 810 of adjacent linkages face in opposite directions,thus creating an accordion-like structure, as shown in FIG. 17 . FIG. 17is a schematic diagram of the unfolding and folding mechanism of thelinkage subset 800 illustrated in FIGS. 16A-16G as it transitionsbetween an active and an inactive configuration. In particular, FIG. 17illustrates a diagrammatic cross-section of the linkage subset 800through the lines A-A shown in FIG. 16G. Unlike the linkages 310described above with reference to FIGS. 5A-7F, the linkages 805 are notslidable relative to one another. Instead, the linkages 805 areconfigured to swivel approximately 180 degrees at the hinge mechanisms(i.e. the hinge pins 815 and hinge tips 810) to fold in anaccordion-like manner from an extended, “zipped,” and activeconfiguration 830 into a more compact, “unzipped.” and inactiveconfiguration 840. Alternating linkages 805 fold in opposite directions.For example, with reference to FIG. 16C, the linkage 805 i swivels aboutthe hinge pin 815 i in the direction of an arrow A6 while the linkage805 j folds about the hinge pin 815 j in the direction of an arrow A5.In the more compact configuration (e.g., the configuration 840 shown inFIG. 17 ), a first surface 842 i of the linkage 805 i rests against asecond surface 844 j of the linkage 805 j, and a first surface 842 j ofthe linkage 805 j rests against a second surface 844 k of the linkage805 k. Referring back to the “zipped” linkage subset 800 shown in FIG.16B-16F, the linkage subset 800 unzips into four distinct,vertically-staggered strips of linkages 805. Just as each car at afour-way stop moves sequentially and independently of one another, thedistal-most linkage 805 of each strip of linkages folds independently ofeach other and in sequence, with the linkages 805 folding down in aspiral in the direction of arrow S1 in FIG. 16F. For example, after thelinkage 805 i folds, the linkage 805 a folds, and then the linkage 805 bfolds, and then the linkage 805 c folds. Each time, the folding linkage805 either locks or unlocks on features (e.g., slot 807 or 808 maycapture the flange portion 825) of its neighboring or adjacent linkage805.

FIG. 18 illustrates a perspective view of an exemplary linkage subset900. FIGS. 19A-19E illustrate various views of the exemplary linkagesubset 900 coupled to an exemplary return assembly 902. In particular.FIG. 19A illustrates a front, partially transparent view of the linkagesubset 900 and the return assembly 902. FIG. 19B illustrates a back viewof the linkage subset 900 and the return assembly 902. FIG. 19Cillustrates a right side view of the linkage subset 900 and the returnassembly 902. FIG. 19D illustrates a top view of the linkage subset 900and the return assembly 902. FIG. 19E illustrates a bottom view of thelinkage subset 900 and the return assembly 902.

The linkage subset 900 is an example of the linkage subset 314 of thevariable-length support assembly 306 described above with reference toFIG. 4 according to one embodiment of the present disclosure. Thelinkage subset 900 comprises several individual linkages 910 coupled toone another to form a portion of a variable-length support assembly. Inthe pictured embodiment, only the linkages 910 a-p are visible, althoughadditional linkages are present in the linkage subset 900. Each of thelinkages 910 is substantially identical to one another, and each linkage910 is shaped as a relatively flat, oblong tab including an aperture912, a projection 914, a flange 916, and multiple slots 918. The flatand generally oblong shape of the linkages 910 and the rounded shapes ofthe apertures 912 and projections 914 should not be considered alimiting feature, as other shapes and configurations are contemplatedfor other embodiments of the present invention. These may include, forexample, round, rectangular, oblong, elliptical, triangular, and squareshapes.

For the sake of simplicity, only the linkage 910 m is described in moredetail. It is to be understood that the linkages 910 are substantiallyidentical. In the pictured embodiment, the linkage 910 m includes anaperture 912 m at one end and a projection 914 m at the opposing end.The aperture 912 may have any shape that corresponds to the projection914 of the adjacent linkage, enabling the projection 914 of one linkageto moveably couple to the aperture 912 of an adjacent linkage. In thepictured embodiment, both the apertures 912 and the projections 914 havea rounded shape. The projection 914 k is moveably coupled to theaperture 912 m. The projections 914 of each linkage 910 are shaped andsized to interact with the apertures 912 of a serially connected linkage910 to create a hinge mechanism that pivotally connects adjacentlinkages 910. Thus, the apertures 912 receive individual projections 914of serially linked linkages 910 whether the linkage subset 900 is in anactive or “zipped-up” configuration or in an inactive or “un-zipped”configuration. The projections 914 are always coupled to the apertures912 to create at least four elongated strips of linkages 910 thatinteract to form the linkage subset 900.

The linkage 910 m also includes two slots 918 m and a flange 916 m. Theslots 918 are shaped and sized to receive individual flange portions 916of other linkages 910 when the linkage subset 900 is in an active or“zipped-up” configuration. FIGS. 18 and 19A-19C show the linkages 910assembled together in an active or “zipped up” configuration, with theflange portions 916 positioned within the corresponding slots 918.

As best shown by the top and bottom views of the linkage subset 900illustrated in FIGS. 19D and 19E, the linkage subset 900 is formed offour interlocking strips or support members of serially connectedlinkages 910 that are interlocked together at the general midline ofeach strip to form a central lumen 920. The slots 918 receive theflanges 916 of nearby linkages 910, thereby allowing serially connectedrows of linkages 910 to rest snugly against one another at approximatelyright angles to form the central lumen 920. The central lumen 920corresponds to the central lumen 315 described above with reference toFIG. 4 . In the pictured embodiment, the linkage subset 900 includes adistal cap 922 upon which the distal-most linkages are anchored. Otherembodiments may lack such an endcap. As the individual strips oflinkages unzip or unlock, the linkages 910 of each strip swingone-by-one into place as the protruding arm is locked into place by theneighboring linkage's slot (the slot of linkage to the right, forexample). As the strips unzip, the unzipped linkages 910 of eachindividual strip are coiled into a helix into canisters, as describedfurther below.

Returning to FIG. 19A, the return assembly 902 comprises fourcylindrical canisters 924 a-d that are linked together but capable ofindependent rotation about central bars 926 a-d, respectively. As shownin FIG. 19A, as the linkage subset 900 “unzips” or transitions from anexpanded, “zipped” configuration into a more compact, “unzipped”configuration (i.e. as the return assembly 902 advances in a distaldirection down the linkage subset 900), the individual strips or supportmembers of serially-connected linkages 910 wind around the central bars926 a-d and into the canisters 924 a-d, thereby shortening the length ofthe variable-length support assembly of which the linkage subset 900 isa part. The unzipping of the linkage strips occurs asynchronously in thesense each linkage of a strip becomes unlocked or decoupled from thelinkage of an adjacent strip in a one-at-a-time, serial progression. Inthis example, each linear support member or strip of linkages 910 windsinto a separate canister 924 a-d. For example, in FIG. 19A, the linkages910 b, 910 e, 910 h, 910 o, 910 k, and 910 m form a single supportmember or strip of linkages that is shown winding into the canister 924a of the return assembly 902 about the central bar 926 a in thedirection of arrow A7. Unlike the linkages 310 described above withreference to FIGS. 5A-7F, the linkages 910 are not slidable relative toone another. Instead, the linkages 910 are configured to rotate at thehinge mechanisms created by the projections 914 and the apertures 912 tounlock and wind from an extended, “zipped,” and active configurationinto a more compact. “unzipped,” and inactive configuration (i.e., whenat least some linkages 910 coil into the return assembly 902).

FIG. 20 illustrates a perspective view of an exemplary linkage subset1000 coupled to an exemplary return assembly 1002. FIGS. 21A-21Eillustrate various views of the exemplary linkage subset 1000 coupled tothe exemplary return assembly 1002. In particular, FIG. 21A illustratesanother perspective view of the linkage subset 1000 and the returnassembly 1002. FIG. 21B illustrates the same perspective view as FIG.21A of the linkage subset 1000 with a transparent view of the returnassembly 1002. FIG. 21C illustrates a front view of the linkage subset1000 and a transparent view of the return assembly 1002. FIG. 21Dillustrates a right side view of the linkage subset 1000 and the returnassembly 1002. FIG. 21E illustrates a left side view of the linkagesubset 1000 and the return assembly 1002. FIG. 21F illustrates a topview of the linkage subset 1000 and the return assembly 1002. FIG. 21Gillustrates a bottom view of the linkage subset 1000 and the returnassembly 1002.

The linkage subset 1000 is an example of the linkage subset 314 of thevariable-length support assembly 306 described above with reference toFIG. 4 according to one embodiment of the present disclosure. Thelinkage subset 1000 comprises several individual linkages 1010 coupledto one another to form a portion of a variable-length support assemblyakin to the variable-length support assembly 306 described above withrelation to FIGS. 3 and 4 . In the pictured embodiment, only thelinkages 1010 a-e are illustrated, although additional linkages may bepresent in the linkage subset 1000. Each of the linkages 1010 issubstantially identical to one another, and the linkages 1010 includeprojections 1012 that are sized and shaped to interlock with each other.The shapes of the linkages 1010 and their projections 1012 should not beconsidered limiting features, as other shapes and configurations arecontemplated for other embodiments of the present invention. These mayinclude, for example, round, rectangular, oblong, elliptical,triangular, and square shapes.

Each linkage 1010 is coupled to an adjacent linkage 1010 by a bridgingelement 1015. For example, the linkages 1010 a and 1010 b are linked bythe bridging element 1015 a, the linkages 1010 b and 1010 c are linkedtogether by the bridging element 1015 b, and the linkages 1010 d and1010 e are linked together by the bridging element 1015 c. As shown inFIG. 20 , the linkages 1010 are assembled in two opposite supportmembers or strips 1020 a, 1020 b of linkages 1010 serially coupled bybridging elements 1015. The strips 1020 a. 1020 b define a central lumen1025, as best illustrated in FIGS. which corresponds to the centrallumen 315 described above with reference to FIG. 4 .

The linkages 1010 of the two strips 1020 a, 1020 b are shaped andconfigured such that the linkages 1010 of one strip (e.g., the strip1020 a) can only engage with linkages 1010 of the opposite strip (e.g.,the strip 1020 b) when the projections 1012 are at an appropriate anglerelative to one another. The projections 1012 of linkages 1010 fromopposite strips 1020 a, 1020 b are shaped and sized to overlap andengage one another, thereby interlocking the strips 1020 a, 1020 b asthe linkage subset 1000 assumes an expanded or “zipped up”configuration. The interaction of the projections 1012 prevents the twostrips 1020 a, 1020 b from disengaging from one another along theexpanded length of the variable-length support assembly. The linkages1010 may be engaged or interlocked one at a time, in succession, as thelinkages 1010 emerge from the return assembly 1002. Similarly, thestrips 1020 may be “unzipped” and the linkages 1010 disengaged from oneanother as the linkages 1010 enter the return assembly 1002 and thelinkage subset 1000 assumes a more compact or “unzipped” configuration.

Thus, the return assembly 1002 acts as a movable guide including twochannels 130 a, 1030 b that are angled to guide the individual supportmembers or linkage strips 1020 a, 1020 b, respectively apart from oneanother and through the return assembly 1002. As shown in FIG. 21B, thereturn assembly 1002 includes a central lumen 1032 that allows for thepassage of a medical instrument such as, without limitation, a catheter.As the return assembly 1002 moves in the direction of the arrow A8 shownin FIG. 21C, the linkages 1010 nearest the return assembly 1002encounter a guide element 1035 that nudges the strips 1020 a, 1020 bapart and into the separate channels 1030 a, 1030 b. The guide element1035 is an angular central ridge or projection of the return assembly1002. The linkages 1010 of different strips 1020 a, 1020 b separate fromone another in succession, two at a time, in the direction of the arrowA8. The return assembly 1002 is configured such that by the passage ofthe return assembly 1002 in the direction of the arrow A8, the linkages1010 of opposing strips 1020 a, 1020 b are drawn together andinterlocked, while by the passage of the return assembly 1002 in theopposite direction (i.e., in the direction of an arrow A9), the linkages1010 are disengaged and separated to enter the channels 1030 a, 1030 b.

Although the systems and methods of this disclosure have been describedfor use in the connected bronchial passageways of the lung, they arealso suited for navigation and treatment of other tissues, via naturalor surgically created connected passageways, in any of a variety ofanatomical systems including the colon, the intestines, the kidneys, thebrain, the heart, the circulatory system, or the like. The methods andembodiments of this disclosure are also suitable for non-interventionalapplications.

One or more elements in embodiments of the invention may be implementedin software to execute on a processor of a computer system such ascontrol system 112. When implemented in software, the elements of theembodiments of the invention are essentially the code segments toperform the necessary tasks. The program or code segments can be storedin a processor readable storage medium or device that may have beendownloaded by way of a computer data signal embodied in a carrier waveover a transmission medium or a communication link. The processorreadable storage device may include any medium that can storeinformation including an optical medium, semiconductor medium, andmagnetic medium. Processor readable storage device examples include anelectronic circuit; a semiconductor device, a semiconductor memorydevice, a read only memory (ROM), a flash memory, an erasableprogrammable read only memory (EPROM); a floppy diskette, a CD-ROM, anoptical disk, a hard disk, or other storage device, The code segmentsmay be downloaded via computer networks such as the Internet, intranet,etc.

Note that the processes and displays presented may not inherently berelated to any particular computer or other apparatus. The requiredstructure for a variety of these systems will appear as elements in theclaims. In addition, the embodiments of the invention are not describedwith reference to any particular programming language. It will beappreciated that a variety of programming languages may be used toimplement the teachings of the invention as described herein.

While certain exemplary embodiments of the invention have been describedand shown in the accompanying drawings, it is to be understood that suchembodiments are merely illustrative of and not restrictive on the broadinvention, and that the embodiments of the invention not be limited tothe specific constructions and arrangements shown and described, sincevarious other modifications may occur to those ordinarily skilled in theart.

What is claimed is:
 1. An apparatus for guiding an elongated flexibleinstrument, the apparatus comprising: a first plurality of linkagesforming a first side of a channel of a variable-length support assembly;a second plurality of linkages forming a second side of the channel,opposite the first side; a third plurality of linkages disposed betweenthe first and second plurality of linkages and forming a third side ofthe channel; and a fourth plurality of linkages disposed between thefirst and second plurality of linkages and forming a fourth side of thechannel, opposite the third side; wherein each of the first, second,third, and fourth pluralities of linkages are separable from each otherto transition the variable-length support assembly from an elongatedconfiguration to a compact configuration.
 2. The apparatus of claim 1,wherein the third plurality of linkages is interlocked with the firstand second pluralities of linkages in the elongated configuration. 3.The apparatus of claim 2, wherein the fourth plurality of linkages isinterlocked with the first and second pluralities of linkages in theelongated configuration.
 4. The apparatus of claim 1, whereinadvancement of the variable-length support assembly along a longitudinalaxis defined through the channel causes an asynchronous unlocking of thefirst, second, third, and fourth pluralities of linkages from eachother.
 5. The apparatus of claim 4, wherein the variable-length supportassembly is adapted to maintain a length of the elongated flexibleinstrument in a fixed configuration relative to the variable-lengthsupport assembly as the variable-length support assembly is moved alongthe longitudinal axis.
 6. The apparatus of claim 1, wherein each pair ofadjacent linkages of the first plurality of linkages is connected by ahinge component.
 7. The apparatus of claim 6, wherein each linkage ofthe first plurality of linkages is configured for rotational movementabout the hinge component relative to an adjacent linkage.
 8. Theapparatus of claim 1, wherein the linkages of each of the first, second,third, and fourth pluralities of linkages are connected to axiallyadjacent linkages in a linear formation.
 9. The apparatus of claim 1,further comprising a return assembly configured to receive at least aportion of at least one of the first, second, third, or fourthpluralities of linkages to shorten the variable-length support assemblyas the elongated flexible instrument and the variable-length supportassembly are moved along a longitudinal axis of the variable-lengthsupport assembly.
 10. The apparatus of claim 9, wherein the returnassembly is configured to release at least some linkages of each of thefirst, second, third, and fourth pluralities of linkages to lengthen thevariable-length support assembly as the elongated flexible instrument ismoved along the longitudinal axis in a first direction.
 11. Theapparatus of claim 10, wherein advancement of the return assembly alongthe longitudinal axis in a second direction opposite the first directionseparates a proximal end of the variable-length support assembly suchthat the third and fourth pluralities of linkages are separated from thefirst and second pluralities of linkages, directing each of the first,second, third, and fourth pluralities of linkages into the returnassembly and causing the variable-length support assembly to assume thecompact configuration.
 12. The apparatus of claim 11, wherein directingeach of the first, second, third, and fourth pluralities of linkagesinto the return assembly comprises rotating individual linkages of eachplurality of linkages radially outward from the channel.
 13. Theapparatus of claim 11, wherein directing each of the first, second,third, and fourth pluralities of linkages into the return assemblycomprises rotating individual linkages of each plurality of linkagesabout an axis transverse to the longitudinal axis.
 14. The apparatus ofclaim 11, wherein separating a proximal end of the variable-lengthsupport assembly includes unlocking each linkage from circumferentiallyadjacent linkages by applying a force to each linkage to displace aflange of each linkage from a slot of an adjacent linkage.
 15. Theapparatus of claim 1, wherein each linkage is substantially identical toeach other linkage.
 16. The apparatus of claim 1, wherein when thevariable-length support assembly is in the elongated configuration, aflange of a first linkage of the first plurality of linkages interlockswith a slot of a linkage of the third plurality of linkages, a flange ofthe linkage of the third plurality of linkages interlocks with a slot ofa linkage of the second plurality of linkages, a flange of the linkageof the second plurality of linkages interlocks with a slot of a linkageof the fourth plurality of linkages, and a flange of the linkage of thefourth plurality of linkages interlocks with a slot of a second linkageof the first plurality of linkages.
 17. The apparatus of claim 1,wherein when the variable-length support assembly is in the elongatedconfiguration, a flange of a first linkage of the first plurality oflinkages interlocks with a first slot of a linkage of the thirdplurality of linkages, and a flange of a second linkage of the firstplurality of linkages interlocks with a second slot of the linkage ofthe third plurality of linkages.
 18. The apparatus of claim 17, whereinwhen the variable-length support assembly is in the elongatedconfiguration, a flange of the linkage of the third plurality oflinkages interlocks with a slot of a linkage of the second plurality oflinkages.
 19. An apparatus for guiding an elongated flexible instrument,the apparatus comprising: a first plurality of linkages forming a firstside of a channel of a variable-length support assembly; a secondplurality of linkages forming a second side of the channel; and a thirdplurality of linkages disposed between the first and second plurality oflinkages and forming a third side of the channel; wherein each of thefirst, second, and third pluralities of linkages are separable from eachother to transition the variable-length support assembly from anelongated configuration to a compact configuration.
 20. An apparatus forguiding an elongated flexible instrument, the apparatus comprising: afirst plurality of linkages forming a first side of a channel of avariable-length support assembly, each linkage of the first plurality oflinkages being pivotally coupled to an adjacent linkage of the firstplurality of linkages when the variable-length support assembly is in anelongated configuration and when the variable-length support assembly isin a compact configuration; a second plurality of linkages forming asecond side of the channel, each linkage of the second plurality oflinkages being pivotally coupled to an adjacent linkage of the secondplurality of linkages in the elongated configuration and in the compactconfiguration; a third plurality of linkages forming a third side of thechannel, each linkage of the third plurality of linkages being pivotallycoupled to an adjacent linkage of the third plurality of linkages in theelongated configuration and in the compact configuration; and a fourthplurality of linkages forming a fourth side of the channel, each linkageof the fourth plurality of linkages being pivotally coupled to anadjacent linkage of the fourth plurality of linkages in the elongatedconfiguration and in the compact configuration; wherein, when thevariable-length support assembly is in the elongated configuration, afirst linkage of the first plurality of linkages is interlocked with asecond linkage of the second plurality of linkages, the second linkageis interlocked with a third linkage of the third plurality of linkages,and the third linkage is interlocked with a fourth linkage of the fourthplurality of linkages; and wherein, when the variable-length supportassembly is in the compact configuration, the first linkage is separatedfrom the second linkage, the second linkage is separated from the thirdlinkage, and the third linkage is separated from the fourth linkage.